<!DOCTYPE html>
<html>

<head>
  <title>
    Test CPU performance of the WebGLRenderingContext.bufferSubData binding
  </title>
  <script src="../resources/runner.js"></script>
</head>

<body>
  <canvas id="canvas" width=400 height=400></canvas>
  <script>
    const canvas = document.getElementById('canvas');
    const gl = canvas.getContext('webgl');

    const vertexBuffer = gl.createBuffer();

    const data = new Float32Array([
      0.0, 0.5, 0.0,
      -0.5, -0.5, 0.0,
      0.5, -0.5, 0.0,
    ]);
    const dataCopy = new Float32Array([
      0.0, 0.5, 0.0,
      -0.5, -0.5, 0.0,
      0.5, -0.5, 0.0,
    ]);
    const sizeInBytes = data.length * data.BYTES_PER_ELEMENT;

    gl.bindBuffer(gl.ARRAY_BUFFER, vertexBuffer);
    // Ensure twice the size of `data`.
    gl.bufferData(gl.ARRAY_BUFFER, sizeInBytes * 2, gl.STATIC_DRAW);

    const iterations = 10000;
    PerfTestRunner.measureInnerRAFTime({
      description: `CPU time for ${iterations * 2} calls to WebGLRenderingContext.bufferSubData`,
      warmUpCount: 10,
      run() {
        for (let i = 0; i < iterations; ++i) {
          gl.bufferSubData(gl.ARRAY_BUFFER, 0, data);
          gl.bufferSubData(gl.ARRAY_BUFFER, sizeInBytes, dataCopy);
        }
      }
    });
  </script>
</body>

</html>
